Conventionally, the type of coffee maker described above has two stages of operation. When the power to the coffee maker is turned on, the heating element is activated, and a temperature of the heating system is thermostatically controlled. When the heating system has reached a desired temperature, this is indicated to the user, for example by illumination of a lamp. From then on, the user may select when the coffee is to be brewed, by operating a switch which activates the pump to drive the hot water through the coffee filter device.
One example of this type of coffee maker is shown in GB 1 538 238, which discloses a coffee maker for brewing coffee comprising a water reservoir, a heating chamber and a pump which pumps water from the reservoir through the heating chamber to a filter device, the heating chamber being provided with a temperature sensor. The temperature sensor is provided for regulating the water temperature within the heating chamber.